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Related papers: Smoothed Complexity of 2-player Nash Equilibria

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We show that the problem of finding an {\epsilon}-approximate Nash equilibrium in an anonymous game with seven pure strategies is complete in PPAD, when the approximation parameter {\epsilon} is exponentially small in the number of players.

Computer Science and Game Theory · Computer Science 2014-12-19 Xi Chen , David Durfee , Anthi Orfanou

We consider (i) the problem of finding a (possibly mixed) Nash equilibrium in congestion games, and (ii) the problem of finding an (exponential precision) fixed point of the gradient descent dynamics of a smooth function $f:[0,1]^n…

Computational Complexity · Computer Science 2021-03-24 Yakov Babichenko , Aviad Rubinstein

We prove that it is PPAD-hard to compute a Nash equilibrium in a tree polymatrix game with twenty actions per player. This is the first PPAD hardness result for a game with a constant number of actions per player where the interaction graph…

Computer Science and Game Theory · Computer Science 2020-02-28 Argyrios Deligkas , John Fearnley , Rahul Savani

Noncooperative game theory provides a normative framework for analyzing strategic interactions. However, for the toolbox to be operational, the solutions it defines will have to be computed. In this paper, we provide a single reduction that…

Computer Science and Game Theory · Computer Science 2007-05-23 Vincent Conitzer , Tuomas Sandholm

Equilibria of realistic multiplayer games constitute a key solution concept both in practical applications, such as online advertising auctions and electricity markets, and in analytical frameworks used to study strategic voting in…

Computer Science and Game Theory · Computer Science 2025-11-18 Jakub Černý , Shuvomoy Das Gupta , Christian Kroer

In an $\epsilon$-Nash equilibrium, a player can gain at most $\epsilon$ by unilaterally changing his behaviour. For two-player (bimatrix) games with payoffs in $[0,1]$, the best-known$\epsilon$ achievable in polynomial time is 0.3393. In…

Computer Science and Game Theory · Computer Science 2014-10-02 Argyrios Deligkas , John Fearnley , Rahul Savani , Paul Spirakis

In general, Nash equilibria in normal-form games may require players to play (probabilistically) mixed strategies. We define a measure of the complexity of finite probability distributions and study the complexity required to play Nash…

Computer Science and Game Theory · Computer Science 2024-05-14 Edan Orzech , Martin Rinard

We study the problem of computing an $\epsilon$-approximate Nash equilibrium of a two-player, bilinear game with a bounded payoff matrix $A \in \mathbb{R}^{m \times n}$, when the players' strategies are constrained to lie in simple sets. We…

Optimization and Control · Mathematics 2026-01-08 Ishani Karmarkar , Liam O'Carroll , Aaron Sidford

We know that the Nash equilibria of a game cannot be computed efficiently unless $P = PPAD$. But can they be learned? Are there dynamics that (1) can be computed efficiently by the players at each strategy profile and (2) are guaranteed to…

Computer Science and Game Theory · Computer Science 2026-04-17 Oliver Biggar , Christos Papadimitriou , Georgios Piliouras

The framework outlined in [arXiv:2010.13024] provides an approximation algorithm for computing Nash equilibria of normal form games. Since NASH is a well-known PPAD-complete problem, this framework has potential applications to other $PPAD$…

Computer Science and Game Theory · Computer Science 2021-10-27 Aadesh Salecha

We prove communication complexity lower bounds for (possibly mixed) Nash equilibrium in potential games. In particular, we show that finding a Nash equilibrium requires $poly(N)$ communication in two-player $N \times N$ potential games, and…

Computer Science and Game Theory · Computer Science 2020-11-16 Yakov Babichenko , Aviad Rubinstein

We prove that computing an $\epsilon$-approximate Nash equilibrium of a win-lose bimatrix game with constant sparsity is PPAD-hard for inverse-polynomial $\epsilon$. Our result holds for 3-sparse games, which is tight given that 2-sparse…

Computational Complexity · Computer Science 2026-02-23 Eleni Batziou , John Fearnley , Abheek Ghosh , Rahul Savani

We present a simple primal-dual algorithm for computing approximate Nash-equilibria in two-person zero-sum sequential games with incomplete information and perfect recall (like Texas Hold'em Poker). Our algorithm is numerically stable,…

Computer Science and Game Theory · Computer Science 2015-12-24 Elvis Dohmatob

Computing Nash equilibrium in multi-agent games is a longstanding challenge at the interface of game theory and computer science. It is well known that a general normal form game in N players and k strategies requires exponential space…

Computer Science and Game Theory · Computer Science 2021-12-09 Morris Yau

We study the query complexity of approximate notions of Nash equilibrium in games with a large number of players $n$. Our main result states that for $n$-player binary-action games and for constant $\varepsilon$, the query complexity of an…

Computer Science and Game Theory · Computer Science 2014-07-21 Yakov Babichenko

We study the complexity of computing stationary Nash equilibrium (NE) in n-player infinite-horizon general-sum stochastic games. We focus on the problem of computing NE in such stochastic games when each player is restricted to choosing a…

Computer Science and Game Theory · Computer Science 2022-11-30 Yujia Jin , Vidya Muthukumar , Aaron Sidford

We analyse the computational complexity of finding Nash equilibria in turn-based stochastic multiplayer games with omega-regular objectives. We show that restricting the search space to equilibria whose payoffs fall into a certain interval…

Computer Science and Game Theory · Computer Science 2015-07-01 Michael Ummels , Dominik Wojtczak

We analyse the computational complexity of finding Nash equilibria in simple stochastic multiplayer games. We show that restricting the search space to equilibria whose payoffs fall into a certain interval may lead to undecidability. In…

Computer Science and Game Theory · Computer Science 2010-06-24 Michael Ummels , Dominik Wojtczak

Studying Nash dynamics is an important approach for analyzing the outcome of games with repeated selfish behavior of self-interested agents. Sink equilibria has been introduced by Goemans, Mirrokni, and Vetta for studying social cost on…

Computer Science and Game Theory · Computer Science 2009-02-04 Vahab Mirrokni , Alexander Skopalik

We investigate the complexity of bounding the uncertainty of graphical games, and we provide new insight into the intrinsic difficulty of computing Nash equilibria. In particular, we show that, if one adds very simple and natural additional…

Computer Science and Game Theory · Computer Science 2012-07-09 Gianluigi Greco , Francesco Scarcello